lml@lancaironline.net Mailing List Archive

Yes - of course a secondary (or safety) latch COULD hinder egress, but it MAY NOT and in fact SHOULD NOT if it is cleverly / properly designed in accordance with our design criteria. If it does materially hinder egress – its a BAD design – and should not be considered further. I would have thought that was obvious.

Does a regular car door latch hinder egress? Apart from the fact that you have to pull the handle, I think the answer is “no” unless you drive a car with two internal (may be even three) and two external door handles on a single door which all need to opened on either side to get the door open! Actually – has anyone ever inadvertently knocked that little switch usually at the front of the arm rest in amongst the electric window switches – and then parked up and tried to open the door…hmmmmm. Seems like a lot cars have that feature – so, seems like a bad design if you had to get out in a hurry!! More than a few million recalls required….

But let’s stick with the concept of the mechanical car door latch (and forget the electric safety lock) - what happens when the car door swings shut or it is gently closed, but not quite hard enough for it to completely latch? If we could come up with something like that, and provided moving either of the internal or external canopy handles to the open position releases the latches – that would more than satisfy our design criteria, would it not?

I can assure you that for my part, avoiding a deleterious "secondary consequence” such as hindering egress or external emergency access is and has been front of mind for months - and I’d be very surprised if that was any different to others looking at this. Trouble is – trying to find a solution that achieves this simply with the minimum of modification to the existing mechanism / components is proving elusive. Apart from a complete redesign of the current claw assembly to act a like a regular car door latch, I’m running out of ideas…… Anyone else got any ideas (that won’t unduly hinder egress)?

Regards,

John

John N G Smith
Tel / fax:    +61-8-9385-8891
Mobile:      +61-409-372-975
Email:         john@jjts.net.au

From: Kevin Stallard <kevin@arilabs.net>
Reply-To: Lancair Mailing List <lml@lancaironline.net>
Date: Friday, 2 May 2014 7:26 pm
To: <lml@lancaironline.net>
Subject: [LML] Re: Legacy White Paper

This would work except there is a consequence for adding a secondary latch.

The only issue I have with it is that a secondary latch could prevent someone from exiting the airplane when they need to in a hurry. Just like the pole problem, if the latch prevents someone from exiting the airplane (in the case of a fire, for example), then is it worse or better than having the canopy open in flight?

Unlike moving utility poles, there is a secondary consequence for adding a latch.

Thanks,
Kevin

________________________________________
From: Lancair Mailing List [lml@lancaironline.net] On Behalf Of Gary Casey [casey.gary@yahoo.com]
Sent: Thursday, May 01, 2014 5:40 AM
To: lml@lancaironline.net
Subject: [LML] Re: Legacy White Paper

Although I'm not directly affected, not being a Legacy owner, I feel the need (okay, urge) to put in my 2 cents worth. This discussion reminds me of one I had once with a safety expert that was giving some reasons for the much lower vehicle accident rate here than in Europe. She said that one factor is that here we are uniformly moving light poles away from roadways. She pointed to a pole that was next to the street and said, "that pole will kill someone someday. We don't know when, but it will. That's why we're moving it." There was no discussion of the fault or even why someone might die, just a statement of fact. I think the same is true of the canopy problem. The incorporation of a secondary latch will result in fewer deaths. You can argue about the pilot's (as a group) skill level, or their attention to checklists or warning lights, but in the end there will be more people alive if secondary latches are there. Isn't that enough reason to go ahead with it?
Just my thought on the subject.
Gary Casey

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